diff --git a/devicemodel/hw/pci/xhci.c b/devicemodel/hw/pci/xhci.c
index fb1e22edc..75623d523 100644
--- a/devicemodel/hw/pci/xhci.c
+++ b/devicemodel/hw/pci/xhci.c
@@ -2423,6 +2423,11 @@ pci_xhci_cmd_set_tr(struct pci_xhci_vdev *xdev,
 	cmderr = XHCI_TRB_ERROR_SUCCESS;
 
 	dev = XHCI_SLOTDEV_PTR(xdev, slot);
+	if (!dev) {
+		UPRINTF(LDBG, "%s slot is not enabled!\r\n", __func__);
+		cmderr = XHCI_TRB_ERROR_SLOT_NOT_ON;
+		goto done;
+	}
 	UPRINTF(LDBG, "set_tr: new-tr x%016lx, SCT %u DCS %u\r\n"
 		 "      stream-id %u, slot %u, epid %u, C %u\r\n",
 		 (trb->qwTrb0 & ~0xF),  (uint32_t)((trb->qwTrb0 >> 1) & 0x7),